Device for cutting lengths from elongated, in particular tubular, material



Aug. 27, 1957 H. BECKER ETAT. 2,804,142

DEVICE FoR CUTTING LENGTHS FROM ELONGATED, 1N

PARTICULAR TUBULAR, MATERIAL AFiled-Sept. 15, 1954 5 Sheets-Sheet 1 v\-4 7 5 5 7 QTL y 1N V EN TORS Aug. 27, 1957 2,804,142 D, IN

5 Sheets-Sheet 2 H. BECKER ETAL DEVICE FOR CUTTING LENGTHS FROM ELONGATEPARTICULAR TUBULAR, MATERIAL Filed Sept. 15, 1954 LP. -1E

Allg 27, 1957 H. BECKER ErAL 2,804,142

DEVICE FOR CUTTING LENGTHS FROM ELONGATED, IN

PARTICULAR TUBULAR, MATERIAL 5 Sheets-Sheet 3 Filed Sept. 15, 1954#Mamma/14a BY y IN V EN TOR!)` llg. 27, 1957 H, BECKER ETAL 2,804,142 i`DEVICE FOR CUTTING LENGTHS FROM ELONGATED, IN

PARTICULAR TUBULAR, MATERIAL Filed Sept. 15, 1954 5 Sheets-Sheet 4 IN VEN TORS H. BECKER ET Al..

Aug. 27, 1957 2,804,142

DEVICE FOR CUTTING LENGTHS FROM ELONGATED, IN

PARTICULAR TUBULAR, MATERIAL 5 Sheets-Sheet 5 Filed Sept. 15, 1954INVENTORS Hg? @wir TT United gratas Patent DEVlClE FR CUTTNG LENGTHSFROM ELON- LGTED, 1N PARTCULAR TUBULAR, MATE- REAL Hans Becker andTheodor Noppen, Dusseldorf-Heerdt, Germany; said Noppen assigner to saidBecker Application September 15, 1954, Serial No. 456,266

Claims priority, appiication Germany September 17, 1953 Claims. (Cl.164-60) There is a known cut-olf machine with internally placed cuttingtools, wherein the tool element, during the cut-off operation, revolvesupon a center eccentrically located with respect to the centerline ofthe part to be cut, the said center being displaced about the centerlineof the stationary tubular work by means of a feed mechanism such thatthe `frame bearing the tool element is driven by two cranks withadjustable throws. vIn the known machine, the pins of the cranks are atrst in a position concentric with their drive shafts. During the cycleof operation, they are uniformly adjusted to increasing crank radius lbyfeed means provided on their shafts, while the two cranks are in uniformrotation.

In addition to the fact that the resetting of crank pins required duringthe cycle of operation -is a diicult problem calling for complexdevices, these known cut-olf machines are subject to disadvantages inoperation; for, while the tool element is lbeing eccentrically revolvedabout the work to be cut, by means of the cranks, its cutting toolsgradually enter, spirally as it were, deeper and deeper Ainto the work,until nally, in the last crank revolution, the Work is actually cut off.In this process, the tools always act almost tangentially on the work,so that they are -obliged to cut chips commencing at an extremelyunfavorable angle, with zero chip thickness.

The invention is intended to overcome the disadvantages mentioned andprovide favorable chip conditions in that the `eccentricity of the crankpins is initially set to a favorable value for purposes of chipformation and detachment, the eccentrics or cranks not being set inrotation until a later point. Accordingly, the invention relates to adevice for cutting lengths from elongated, in particular tubular,material, wherein an annular tool element equipped with several cuttingtools revolves, during the cut-o operation, upon a center eccentricallylocated with respect to the centerline of the tubular work, the saidcenter 4being `displaced about the centerline of the said stationarywork by means of a feed mechanism, such that the frame bearing the toolelement is driven by two cranks with adjustable throws; and consistssubstantially in that each of the cranks comprises an eccentric shaftrotatable in an eccentric bearing, and the said shaft and bearing are ineach instance displaceable by means of a common mechanism.

lIn practicing the invention, the arrangement may advantageously be suchthat only one mechanism permanently connected with one of the adjustingmeans, for example the eccentric bearings, is provided, this mechanismbeing connectable to the other adjusting means, for example theeccentric shafts, by means of a disengageable coupling. Adjustment ofeccentricity of the two cranks is in that case efiected -by turning oneadjusting system, the cranks being set in rotation by connecting theother adjusting system to the drive as well.

The drive for the eccentric bearings rotatable on the eccentric shaftsis provided, according to the invention, in that each eccentric bearingis fitted with an internal gear concentric with its bore, which gear isengaged by 2,3%,142 Patented Aug. 27, 1957 a pinion mounted on the stubof the corresponding eccentric shaft. For rotation of the eccentric`bearings and shafts, worm gears may advantageously be provided,preferably of self-locking type.

As a result `of the fact that in the device according to the invention,the eccentric Vfeed movement does not begin until after the tool, byvirtue of its eccentric setting, has already penetrated the work to thedepth required 4for parting, the individual cutting tools have a veryfavorable angle of entry Ifor cutting the chips. This advantage becomes`fully effective especially when the tool element of the device isprovided with a sufficiently small number of cutting tools so thatduring the cut-off process, only one tool is in the cut at a time. As aresult, with low lsetting pressure, heavy chips are obtained, ofthickness decreasing from the point of entry in the direction of thecutand therefore of similar shape to the chips obtained in downcutmilling. The low setting pressure required with only one tool in thecut, and the high cutting speed, prevent any deformation of the work,even in the case of thin-walled hollow stock.

An embodiment of the invention is illustrated in the accompanyingdrawings, wherein- Fig. 1 shows a longitudinal section of a pipe-cuttingmachine;

Fig. 2 shows a view of the machine from the left, the lower portion ofthe machine being in section `along the line A-B in Fig. l;

Fig. 3 shows a section along the line C D in Fig. l;

Fig. 4 shows a section along the line E-F in Fig. 2, in a positioncorresponding to Fig. 3;

Fig. 5 shows a View of the machine in the direction of the arrow P inFig. 1, the lower portion of the machine being in section along the lineG-H in Fig. 4;

Figs. 6-8 are views as in Fig. 5, corresponding to different phases ofoperation of the machine.

The machine as shown in Figs. l and 2 comprises a supporting frameworkIand a tool holder mounted thereon. The framework accommodates the driveand a gear for adjustment and control of the movements of the toolholder. The tool holder contains the revolving tool element and drivemechanism thereof. First, the surlmounting tool holder Will bedescribed.

A motor 1 having a V-belt sheave 2 drives a sheave 4 by means of V-belts3, the said sheave 4 'being connected r to a tubular sleeve S. Thesleeve 5 is rotatedly mounted by means lof ball bearings 6 and '7 in thetool holder S, and is provided at its left-hand face with clamps 9 tohold tools 1t). The motor 1 rests on an upper surface of the tool holder8. The tool holder 8 is of symmetrical construction, having two armspointed obliquely downward, of the shape seen in the left-hand half ofFig. 6.

In the supporting framework of the machine, there is a motor 11, forexample `a anged motor as in Fig. 2. This motor is connected by a clutchwith a shaft 12 bearing a gear 13 longitudinally displaceable but notrotatable thereon. The gear 13 is in permanent engagement with a gear 14of double width, connected by a shaft 1S with another gear 16. The gear16, as shown in Fig. 3, engages a gear 17 connected by a shaft 18 withtwo worms 19, 2i). The worms 19 and 2t) are in engagement with thepinions 21 `and 22 shown in Fig. 4. The pinions 21, 22 are each integralwith a gear 21a and 22a, respectively. These gears engage internal gears23, 24, of which gear 23 is Imounted on an eccentric bearing 2S, andgear 24 on an eccentric bearing 2o.

Gear 13, in the position shown in Fig. 2, engages not only the doublegear 14, ybut also another gear 27, intermediate between it and a gear28 (Fig. l). The gear 28 is on a shaft 29 and drives two worms 30, 31(Fig. 3). The worms 30, 3l are in engagement with worm pinions 32, 33(Fig. 4), each of which is coupled with an eccentric shaft 34 or 35,respectively. The stubs'of eccentric shafts 34, 35 bear the worm gearsand pinions 22, 22av and 21, 21a, respectively, in rotatable condition;the eccentric portions of shafts, 34, 3'5 .bear eccentric bearings 25,26. The internal gears 23, 24 of eccentric bearings 25, 26 areconcentric with `the bores of the bearings. yEccentric bearings 25, 26carry the oblique, downward pointed arms of the tool holder 8.

lBy shifting gear 13 on shaft 12, the latter can `be brought out ofengagement with the intermediate gear 27. For this purpose, a crank 39provided on a shaft 36 engages a groove 40 in the hub of gear 13. VShaft36V bears a lever 37 by means of which crank 39 may be actuated. Shaft36 also bears a locking member 38 which, upon setting of the lever 37,is so displaced that when gear 13 is thrust to the right, in the senseof Fig. 2, it engages the teeth of intermediate gear 27 and secures itagainst rotation; whereas in the position of gear 13, shown in Fig. 2,it is swung out of locked position.

The eccentricities of eccentric shafts 34, 35 and eccentric bearings 25,26 are equal, so that the eccentric position of the bores in the tool'holder 8 relative to the stubs of eccentric shafts 34, 35 can beadjusted between zero and the sum of the eccentricities -of theeccentric shafts and bearings by rotating these parts relative t-o eachother. l

4The machine described serves for cutting lengths from hollow stock. Thehollow material to be cut up, for example a pipe, is clamped in themachine in a position in which it is fed into the machine from aconveyor or the like. It may lbe clamped by means of any known type offixture, which may be opera-ble by hand lor by means of a pressuremedium. In Fig. 2, such a clamping means is indicated merelyschematically; no details are shown, these -being irrelevant to theinvention. Y

The machine described operates as follows. After insertion of the pipeto be cut, the latter is clamped by means of the fixture, the toolIholder 8 'being in the position shown in Figs. and 6, where the cuttingtools 10 do not interfere with insertion of the pipe. Then, the motor 1is switched on, thus causing rotation of sleeve 5 with tools 10. Beforethe other motor 11 is switched on, the hand lever 37 is actuated toshift gear 13 to the right, in the sense of Fig. 2 so as to cease to bein engagement with gear 27.

As soon as motor 11 is switched on, the two worms 19, 20 are driven bygears 13, 14 and 16, 17, so that the worm gears 21, 22 and pinions 21a,22a will turn internal gears 23, 24, and hence also the eccentricbearings 25, 26. Consequently, the two bores of the tool holder 8 areplaced eccentrically to the stubs ofthe eccentric shafts 34, 35. In thismanner, the tool head 5, 9, is likewise moved eccentrically to the pipeto be cut, so that its tools 10 cut intothe work. This process isillustrated in Fig. 7. 4In the left-hand part of Fig. 7, it is shownthat the eccentric rbearing 25 has been turned from its initial positionshown in Fig. 6 through about 135 counterclockwise with respect to theeccentric shaft 34. Despite this rotation, the gears 21a, 22a remain inengagement with the internal gea-rs 23, 24, since the latter are placedconcentrically to the bores of eccentric bearings 25, 26. rllhis may beseen inthe right-hand part of Fig. 7. i

When the cutting tools 10 have penetrated the Work to a sufcient depth,the lever 37 is actuated and the drive for worms 30, 31 connected by ashift of gear 13. Consequently, motor 11 now turns the eccentric shafts34, 35 also. Since the transmission ratios for vworms 19, `and worms 30,31 are identical, eccentric shafts 34, 35 and bearings 25, 26 will nowturn jointly at the same rotational speed. The selected resultanteccentricity is thus preserved, and the tool holder 8 is so revolvedabout the work, in yaccordance with the adjusted crank radius, that thetool element will move eccentrically about the centerline of the pipe tobe cut and progressively cut off the pipe circumferentially.

As Figs. 7 and 8 show, in the course of this cutting process, theindividual tool bits 10 act on the work at a favorable angle, withresulting favorable chip formation. Since the individual bits 10 remainin the cut vfor only Ia short period, there is a comparatively largeproportion of time in which they can cool. Consequently, the rotationalspeed of the cutter head can be very high, so that extraordinarily highcutting speed can be obtained with the machine according to theinvention. Since, during the cutting, there is penetration of the wallof the tubular stock to be cut throughout, the formation of a continuousburr is avoided, thus practically eliminating breakage of tool bits.

What we claim is:

1. A'device for cutting lengths from tubular and other elongatedmaterial, comprising a supporting framework, a clamping device for theelongated material, an annular tool with a plurality of cutters at theinner periphery, said tool enclosing said elongated material, a toolholder for supporting said annular 4tool to be rotatable around itscentral axis, a drive means for rotating said tool, two cranks mountedon the supporting framework and engaging with their crank `shafts inrecesses of the tool holder, each of said cranks having an eccentricshaft rotatable in an eccentric bearing, drive means for rotating thetwo eccentric bearings in the same sense of rotation and other drivemeans -for driving the two eccentric shafts in the same direction and atthe same speed with the eccentric bearings, whereby the radii of the twocranks are cornmonly adjustable by one of said drive means and that uponsimultaneous operation of both drive means both cranks are uniformlyrotated so that the tool holder has a motion imparted thereto wherebythe axis of rotation of the tool will move on a cylindrical path aroundthe axis of the elongated material.

2. A device according to claim l wherein a common motor is used foroperation of said first and of said second drive means, andadisengageable coupling is provided which permits the alternativeoperation of one or both drive means by said motor.

3. A device according to claim 2 wherein said drive means include foreach eccentric bearing an internal gear concentric with the bore of saidbearing, and a pinion, provided on the stub of the correspondingeccentric shaft, mounted for rotation thereon, said pinion being inengagement with said internal bore.

4. A device according to claim 3 in which both the first drive means andthe second drive means comprise two worms and worm gears.

5. A device yaccording to claim l, which comprises a cutter head havingsuch a number of bits that during the cutting operation only 4one bit iscutting at a time.

References Cited in the le of this patent UNITED STATES PATENTS

